With all of the various ratings of the best frequent flyer programs, I am wondering if there has been any discussion/evaluation of how good a job these partnerships do in actually getting the miles credited to one's account. In the last year I have had problems with Air Canada posting miles to my United Mileage Plus account and with Singapore Airlines posting miles. These happen to be the only two times I have not used United so the record (from my experience) is not that good in that I had to make the effort both times to keep examing my account for six weeks, keeping the receipts, and mailing in the request. Not exactly the experience one expects as the airlines tout their valuable partnerships. Just wondering where the problems are and which alliances do better than others.